Ok, you will need to go into your blockland folder, most likely at C:\Blockland or C:\Program Files\Blockland. Meaning click Start > My Computer > Click the C: drive and find Blockland there or in Program Files.
Then go into saves and find the save you want to put on the forums or where ever. In this case, you're uploading your save. So go into forum you wish to upload it, and then click New Topic. Once you enter the Topic Creation Menu, simply type out the Subject and Message. Then click Additional Options. You will then click Choose File, which will open up a window that will allow you to navigate to your save. Then you simply find your save, select it, then click open.
Then it will pop-up down there in the additional options are. Preview your post before posting to verify spelling errors and grammar errors. Then, once you are happy with your post, click Post.
@PHFlack: You hardly help this situation by questioning others. Your "What does 'u' mean?" remark a few post up was unnecessary. Please stop trying to be a smart ass and just answer the question in a understandable manner.
To answer your question "What does that have to do with anything?" It was leading towards where his install directory is.